This invention relates to a turbomachine lubricating oil system, and in particular, to a lubricating oil system incorporating a structural support member of the turbomachine.
In turbomachinery, a gear or other rotating member having a relatively large diameter and operable at a relatively high velocity, will produce foaming or frothing of the oil if moved through a body thereof. To avoid the foaming problem, a spray of cooling oil is directed at the gear to lubricate and cool the same. This eliminates the need for a pool or reservoir of oil within the gear box for adequate lubrication of same. The spray of oil contains some air. If the oil were to collect within the gear box due to improper drainage, the oil-air mixture would froth or foam due to turbulence produced as the gear moves through the pool of oil.
If the oil drains from the housing or casing through a relatively small diameter conduit and a pool of oil were to form, frothing or foaming of the oil will increase the back pressure within the conduit thereby preventing free flow of oil therethrough. The increased resistance to oil flow through the conduit will result in a further backup of the oil within the casing. Excess oil within the casing increases the horsepower required to rotate the member through the oil. This in turn reduces the overall operating efficiency of the turbomachine.
Accordingly, it is desirable to enable the oil to freely drain from a casing and to minimize frothing of the oil prior to the oil entering a conduit for return to an oil reservoir.